Jack Herer(b. 1939) is the author of The Emperor Wears No Clothes, a book which has been used in efforts to decriminalize cannabis.

A former Goldwater Republican, Herer is now a pro-marijuana and hemp activist. He has written two books, the aforementioned The Emperor Wears No Clothes and Grass. There has also been a documentary made about his life. He believes that the hemp plant should be decriminalized because it has been shown to be a renewable source of fuel, food, and medicine, and can be grown in virtually any part of the world. He has devoted his life to the support of cannabis, hemp and marijuana.

Jack Herer is also the name given to a specific strain of cannabis that is considered by Herer to be among the world's finest.